“Two or three years ago, we went out and said a storm is coming (Sunday), but not until the afternoon session.” Eubank said. “You're fine (in the morning).”

The next day, Eubank awoke to a tempest of rain mixed with snow. Later on when he saw video footage of the umbrellas and shivering families, the weatherman felt guilty.

“You just said less than 24 hours ago that people would be OK for the morning session, but the storm came early. It’s a cold Sunday morning and you are just kicking yourself,” said Eubank, who heard about his forecast through email, on Facebook and even at church meetings the following week. “We do our very best to give the most accurate forecast, then it bites you, and you’re like, conference weather."

Each April and October, The Church of Jesus Christ of Latter-day Saints hosts tens of thousands of people at general conference. Because thousands are standing in lines at the Conference Center, the weather reports for those important weekends are some of the most scrutinized all year long. And year after year, despite high-tech instruments and equipment, the conference weekend weather has been consistently inconsistent, the KSL meteorologist said.

“Inevitably, the weather is volatile,” Eubank said. “It has nothing to do with general conference; it has to do with the time of the year.”

Historical trends

In the summer of 1983, R. Clayton Brough and David R. James published an in-depth study (Conference vs. the Weather) on weather patterns surrounding general conference. This study was updated in 2006.

According to the report, the earliest weather report came during the April 6-8, 1842, conference held in Nauvoo, Ill. Church members recorded, “the sun shone clear, warm and pleasant. The snow has nearly all disappeared (and) ice (is) about two feet (thick) on (the) Mississippi River.”

Since 1888, all annual and semiannual conferences have been held on or next to Temple Square in Salt Lake City, except for one instance when a major flu epidemic forced the cancellation of the 1957 October conference.

Citing data from the National Weather Service over a 118-year period (1888-2005), the report says 53 percent of all general conferences held in Salt Lake City have experienced wet weather.

April tends to get more moisture than October. The report indicates 64 percent (76 of 118) of April conferences have received measurable precipitation. In contrast, 58 percent (69 of 118) of all October conferences have reported dry conditions.

Other findings include:

The wettest conference weather on record was April 3-6, 1921, when 1.19 inches of precipitation fell. The single wettest conference day was Oct. 10, 1920, with 1.15 inches of moisture.

The snowiest conference period was April 2-6, 1955, when 12.9 inches of snow fell. The single snowiest conference day was April 2, 1995, with 9.6 inches.

The longest dry period for conferences was from October 1999 to October 2002, when no measurable precipitation was recorded for seven consecutive conferences.

April conferences during the past 53 years have typically been under partly cloudy to cloudy skies, with average temperatures in the upper 50s to the lower 60s. For October conferences, the average highs are in the low to mid-70s.

The warmest October conference day was Oct. 7, 1979, at 88 degrees. The coldest October conference day was Oct. 4, 1890, at 30 degrees.

The warmest April conference day was April 5, 1959, at 82 degrees, and the coldest-ever was April 4, 1955, at 20 degrees.

“In essence, April conferences are generally a time for coats and umbrellas,” the report concluded. “October conferences usually enjoy pleasant fall weather.”

Expert opinions

When asked what makes weather so volatile and hard to predict in April and October, several television meteorologists shared their opinions.

Brett Benson, chief meteorologist at KSTU Fox 13, said September/October is a time of the year when the weather transitions from warm patterns to cold patterns, which involves rapid temperature changes, strong winds and storms.

Benson said anything can happen in April because of an opposite transition.

“Some of the biggest weather events in U.S. history have happened in April,” Benson said in an email. “So it’s not just conference weekends that have the corner on the crazy weather market.”

“Surrounded by mountains communities and neighborhoods (at) various elevations and a giant lake full of salt that never freezes over makes for a winter full of potential lake effect events,” Willey said. “The whole thing makes my head spin at times.”

Conference weekend has seen everything imaginable, Eubank said, so be prepared for anything.